Method for making lithium-ion battery electrode material

Abstract

The present disclosure relates to a method for making an electrode material of lithium-ion batteries. In the method, a carbon source compound is dissolved into a solvent to form a liquid phase solution. A number of titanium dioxide particles are provided and are dispersed into the liquid phase solution. The carbon source compound is pyrolyzed, thereby forming a number of carbon coating titanium dioxide particles. A lithium source solution is provided. The lithium source solution and the carbon coating titanium dioxide particles are mixed, according to a molar ratio in a range from about 4:5 to about 9:10, of lithium element to titanium element, thereby forming a sol. The sol is spray dried to form a number of precursor particles. The precursor particles are heated to form a lithium titanate composite electrode material.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims all benefits accruing under 35 U.S.C. §119 from China Patent Application No. 201010110159.0, filed on 2010 Feb. 6, in the China Intellectual Property Office, the contents of which are hereby incorporated by reference.BACKGROUND[0002]1. Technical Field[0003]The present disclosure relates to methods for making electrode material applied in a lithium-ion battery, and particularly to a method for making a lithium titanate composite electrode material.[0004]2. Description of Related Art[0005]Lithium titanate (Li4Ti5O12) with spinel structure is a novel electrode material used in energy storage batteries and has received a great deal of interest recently. Lattice parameters of the lithium titanate have extremely small variations when lithium-ions are cycled in and out during a charging and discharging process of the battery. Thus, the lithium titanate has been reported as a “zero strain” electrode material, and has an ex...

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Benefits of technology

[0007]However, the above precursor is formed by using a solid phase mixing method. The lithium salt and the solid phase titanium dioxide are simply mixed together. As a result, the lithium titanate particles are irregularly shaped and vary in diameter. Thus, the carbon source coated on the surfaces of each of the lithium titanate particles is easily segregated and crystallized during pyrolyzing. Accordingly, a carbon layer, formed by pyrolyzing the carbon source, may non-uniformly coat the surfaces of each of the lithium titanate particles, thereby decreasing electrochemical property of the electrode material of lithium-ion battery.

Problems solved by technology

Electrodes made of lithium titanate can undergo many hundreds of cycles without structural disintegration, thereby increasing the lifespan of the batteries, and decreasing an attenuating speed of the specific capacity of the electrodes.

However, lithium titanate has lower conductivity, charge and discharge rate, and tap density than other electrode materials such as lithium manganate.

Accordingly, a carbon layer, formed by pyrolyzing the carbon source, may non-uniformly coat the surfaces of each of the lithium titanate particles, thereby decreasing electrochemical property of the electrode material of lithium-ion battery.

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